1. Field of the Invention
The present invention relates to a method of designing multiplexing structures for resource allocation to support legacy system, specifically relates to uplink resource unit and a distributed resource allocation method.
2. Discussion of the Background Art
The 802.16m amendment has been developed in accordance with the P802.16 project authorization request (PAR), as approved on 6 Dec. 2006, and with the Five Criteria Statement in IEEE 802.16-06/055r3. According to the PAR, the standard may be developed as an amendment to IEEE Std. 802.16. The 802.16m amendment may provide continuing support for legacy WirelessMAN-OFDMA equipment.
In a conventional IEEE 802.16e system, a basic slot structure and data region is defined as follows: a ‘slot’ in the OFDMA (Orthogonal Frequency Division Multiple Access) PHY requires both time and sub-channel dimension for completeness and serves as the minimum possible data allocation unit. The definition of an OFDMA slot depends on the OFDMA symbol structure, which varies for UL (UpLink) and DL (DownLink), for FUSC (Full Usage of Sub-Channels) and PUSC (Partial Usage of Sub-Channels), and for the distributed sub-carrier permutations and the adjacent sub-carrier permutation (AMC).
For DL FUSC and DL optional FUSC using the distributed sub-carrier permutation, one slot is one sub-channel by one OFDMA symbol. For DL PUSC using the distributed sub-carrier permutation, one slot is one sub-channel by two OFDMA symbols. For UL PUSC using either of the distributed sub-carrier permutations and for DL TUSC1 (Tile Use of Sub-Channels 1) and TUSC2, one slot is one sub-channel by three OFDMA symbols. For the adjacent sub-carrier permutation (AMC), one slot is one sub-channel by two, three, or six OFDMA symbols.
In OFDMA, a data region is a two-dimensional allocation of a group of contiguous sub-channels, in a group of contiguous OFDMA symbols. All the allocation refers to logical sub-channels. A two-dimensional allocation may be visualized as a rectangle, such as shown in FIG. 1.
In the related art, basic data allocation structures and/or pilot structures are different according to permutation rules such as PUSC, FUSC, AMC, etc. This is because permutation rules were separated in the time axis in the related art 16e system so that the structures were designed to be optimized according to each permutation rule. FIG. 2 shows an exemplary related art data allocation structure. Permutation rules are separated in time axis in the related art method. However, if more than one permutation rules exist on the same sub-frame, one unified basic data allocation structure and pilot transmission structure are required.
When multiplexing 16e system and 16m system, it is desirable to design time-frequency granularity of a PRU of a 16m system so that the PRU of the 16m system is compatible with a 16e system. In addition, it is desirable to design multiplexing structures such that performance deterioration of each of the 16e and the 16m system, which are multiplexed together, be made as low as possible.